From db804f23a72bada58f083dfad6a65d019ddb3bd4 Mon Sep 17 00:00:00 2001
From: Li Zefan <lizf@cn.fujitsu.com>
Date: Tue, 10 Jan 2012 16:41:01 +0800
Subject: Btrfs: add pinned extents to on-disk free space cache correctly
I got this while running xfstests:
[24256.836098] block group 317849600 has an wrong amount of free space
[24256.836100] btrfs: failed to load free space cache for block group 317849600
We should clamp the extent returned by find_first_extent_bit(),
so the start of the extent won't smaller than the start of the
block group.
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
---
fs/btrfs/free-space-cache.c | 41 ++++++++++++++++++++---------------------
1 file changed, 20 insertions(+), 21 deletions(-)
(limited to 'fs/btrfs/free-space-cache.c')
diff --git a/fs/btrfs/free-space-cache.c b/fs/btrfs/free-space-cache.c
index ec23d43d0c35..01840ef95a32 100644
--- a/fs/btrfs/free-space-cache.c
+++ b/fs/btrfs/free-space-cache.c
@@ -838,7 +838,7 @@ int __btrfs_write_out_cache(struct btrfs_root *root, struct inode *inode,
struct io_ctl io_ctl;
struct list_head bitmap_list;
struct btrfs_key key;
- u64 start, end, len;
+ u64 start, extent_start, extent_end, len;
int entries = 0;
int bitmaps = 0;
int ret;
@@ -857,25 +857,12 @@ int __btrfs_write_out_cache(struct btrfs_root *root, struct inode *inode,
struct btrfs_free_cluster,
block_group_list);
- /*
- * We shouldn't have switched the pinned extents yet so this is the
- * right one
- */
- unpin = root->fs_info->pinned_extents;
-
/* Lock all pages first so we can lock the extent safely. */
io_ctl_prepare_pages(&io_ctl, inode, 0);
lock_extent_bits(&BTRFS_I(inode)->io_tree, 0, i_size_read(inode) - 1,
0, &cached_state, GFP_NOFS);
- /*
- * When searching for pinned extents, we need to start at our start
- * offset.
- */
- if (block_group)
- start = block_group->key.objectid;
-
node = rb_first(&ctl->free_space_offset);
if (!node && cluster) {
node = rb_first(&cluster->root);
@@ -918,9 +905,20 @@ int __btrfs_write_out_cache(struct btrfs_root *root, struct inode *inode,
* We want to add any pinned extents to our free space cache
* so we don't leak the space
*/
+
+ /*
+ * We shouldn't have switched the pinned extents yet so this is the
+ * right one
+ */
+ unpin = root->fs_info->pinned_extents;
+
+ if (block_group)
+ start = block_group->key.objectid;
+
while (block_group && (start < block_group->key.objectid +
block_group->key.offset)) {
- ret = find_first_extent_bit(unpin, start, &start, &end,
+ ret = find_first_extent_bit(unpin, start,
+ &extent_start, &extent_end,
EXTENT_DIRTY);
if (ret) {
ret = 0;
@@ -928,20 +926,21 @@ int __btrfs_write_out_cache(struct btrfs_root *root, struct inode *inode,
}
/* This pinned extent is out of our range */
- if (start >= block_group->key.objectid +
+ if (extent_start >= block_group->key.objectid +
block_group->key.offset)
break;
- len = block_group->key.objectid +
- block_group->key.offset - start;
- len = min(len, end + 1 - start);
+ extent_start = max(extent_start, start);
+ extent_end = min(block_group->key.objectid +
+ block_group->key.offset, extent_end + 1);
+ len = extent_end - extent_start;
entries++;
- ret = io_ctl_add_entry(&io_ctl, start, len, NULL);
+ ret = io_ctl_add_entry(&io_ctl, extent_start, len, NULL);
if (ret)
goto out_nospc;
- start = end + 1;
+ start = extent_end;
}
/* Write out the bitmaps */
--
cgit
From a1ee5a45818acc7f9c13e560827cf3e8735ac919 Mon Sep 17 00:00:00 2001
From: Li Zefan <lizf@cn.fujitsu.com>
Date: Mon, 9 Jan 2012 14:27:42 +0800
Subject: Btrfs: avoid possible NULL deref in io_ctl_drop_pages()
If we run into some failure path in io_ctl_prepare_pages(),
io_ctl->pages[] array may have some NULL pointers.
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
---
fs/btrfs/free-space-cache.c | 8 +++++---
1 file changed, 5 insertions(+), 3 deletions(-)
(limited to 'fs/btrfs/free-space-cache.c')
diff --git a/fs/btrfs/free-space-cache.c b/fs/btrfs/free-space-cache.c
index 01840ef95a32..4e55af333e19 100644
--- a/fs/btrfs/free-space-cache.c
+++ b/fs/btrfs/free-space-cache.c
@@ -319,9 +319,11 @@ static void io_ctl_drop_pages(struct io_ctl *io_ctl)
io_ctl_unmap_page(io_ctl);
for (i = 0; i < io_ctl->num_pages; i++) {
- ClearPageChecked(io_ctl->pages[i]);
- unlock_page(io_ctl->pages[i]);
- page_cache_release(io_ctl->pages[i]);
+ if (io_ctl->pages[i]) {
+ ClearPageChecked(io_ctl->pages[i]);
+ unlock_page(io_ctl->pages[i]);
+ page_cache_release(io_ctl->pages[i]);
+ }
}
}
--
cgit
From 706efc6630c2722602541a6a2fc5900a4e38456a Mon Sep 17 00:00:00 2001
From: Li Zefan <lizf@cn.fujitsu.com>
Date: Mon, 9 Jan 2012 14:36:28 +0800
Subject: Btrfs: check the return value of io_ctl_init()
It can return -ENOMEM.
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
---
fs/btrfs/free-space-cache.c | 9 +++++++--
1 file changed, 7 insertions(+), 2 deletions(-)
(limited to 'fs/btrfs/free-space-cache.c')
diff --git a/fs/btrfs/free-space-cache.c b/fs/btrfs/free-space-cache.c
index 4e55af333e19..e4eb222147cc 100644
--- a/fs/btrfs/free-space-cache.c
+++ b/fs/btrfs/free-space-cache.c
@@ -637,7 +637,10 @@ int __load_free_space_cache(struct btrfs_root *root, struct inode *inode,
if (!num_entries)
return 0;
- io_ctl_init(&io_ctl, inode, root);
+ ret = io_ctl_init(&io_ctl, inode, root);
+ if (ret)
+ return ret;
+
ret = readahead_cache(inode);
if (ret)
goto out;
@@ -851,7 +854,9 @@ int __btrfs_write_out_cache(struct btrfs_root *root, struct inode *inode,
if (!i_size_read(inode))
return -1;
- io_ctl_init(&io_ctl, inode, root);
+ ret = io_ctl_init(&io_ctl, inode, root);
+ if (ret)
+ return -1;
/* Get the cluster for this block_group if it exists */
if (block_group && !list_empty(&block_group->cluster_list))
--
cgit
From 7fe1e641502616220437079258506196bc4d8cbf Mon Sep 17 00:00:00 2001
From: Li Zefan <lizf@cn.fujitsu.com>
Date: Thu, 29 Dec 2011 14:47:27 +0800
Subject: Btrfs: rewrite btrfs_trim_block_group()
There are various bugs in block group trimming:
- It may trim from offset smaller than user-specified offset.
- It may trim beyond user-specified range.
- It may leak free space for extents smaller than specified minlen.
- It may truncate the last trimmed extent thus leak free space.
- With mixed extents+bitmaps, some extents may not be trimmed.
- With mixed extents+bitmaps, some bitmaps may not be trimmed (even
none will be trimmed). Even for those trimmed, not all the free space
in the bitmaps will be trimmed.
I rewrite btrfs_trim_block_group() and break it into two functions.
One is to trim extents only, and the other is to trim bitmaps only.
Before patching:
# fstrim -v /mnt/
/mnt/: 1496465408 bytes were trimmed
After patching:
# fstrim -v /mnt/
/mnt/: 2193768448 bytes were trimmed
And this matches the total free space:
# btrfs fi df /mnt
Data: total=3.58GB, used=1.79GB
System, DUP: total=8.00MB, used=4.00KB
System: total=4.00MB, used=0.00
Metadata, DUP: total=205.12MB, used=97.14MB
Metadata: total=8.00MB, used=0.00
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
---
fs/btrfs/free-space-cache.c | 235 +++++++++++++++++++++++++++++++-------------
1 file changed, 164 insertions(+), 71 deletions(-)
(limited to 'fs/btrfs/free-space-cache.c')
diff --git a/fs/btrfs/free-space-cache.c b/fs/btrfs/free-space-cache.c
index e4eb222147cc..b3cbb8939fa3 100644
--- a/fs/btrfs/free-space-cache.c
+++ b/fs/btrfs/free-space-cache.c
@@ -2594,17 +2594,57 @@ void btrfs_init_free_cluster(struct btrfs_free_cluster *cluster)
cluster->block_group = NULL;
}
-int btrfs_trim_block_group(struct btrfs_block_group_cache *block_group,
- u64 *trimmed, u64 start, u64 end, u64 minlen)
+static int do_trimming(struct btrfs_block_group_cache *block_group,
+ u64 *total_trimmed, u64 start, u64 bytes,
+ u64 reserved_start, u64 reserved_bytes)
{
- struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
- struct btrfs_free_space *entry = NULL;
+ struct btrfs_space_info *space_info = block_group->space_info;
struct btrfs_fs_info *fs_info = block_group->fs_info;
- u64 bytes = 0;
- u64 actually_trimmed;
- int ret = 0;
+ int ret;
+ int update = 0;
+ u64 trimmed = 0;
- *trimmed = 0;
+ spin_lock(&space_info->lock);
+ spin_lock(&block_group->lock);
+ if (!block_group->ro) {
+ block_group->reserved += reserved_bytes;
+ space_info->bytes_reserved += reserved_bytes;
+ update = 1;
+ }
+ spin_unlock(&block_group->lock);
+ spin_unlock(&space_info->lock);
+
+ ret = btrfs_error_discard_extent(fs_info->extent_root,
+ start, bytes, &trimmed);
+ if (!ret)
+ *total_trimmed += trimmed;
+
+ btrfs_add_free_space(block_group, reserved_start, reserved_bytes);
+
+ if (update) {
+ spin_lock(&space_info->lock);
+ spin_lock(&block_group->lock);
+ if (block_group->ro)
+ space_info->bytes_readonly += reserved_bytes;
+ block_group->reserved -= reserved_bytes;
+ space_info->bytes_reserved -= reserved_bytes;
+ spin_unlock(&space_info->lock);
+ spin_unlock(&block_group->lock);
+ }
+
+ return ret;
+}
+
+static int trim_no_bitmap(struct btrfs_block_group_cache *block_group,
+ u64 *total_trimmed, u64 start, u64 end, u64 minlen)
+{
+ struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
+ struct btrfs_free_space *entry;
+ struct rb_node *node;
+ int ret = 0;
+ u64 extent_start;
+ u64 extent_bytes;
+ u64 bytes;
while (start < end) {
spin_lock(&ctl->tree_lock);
@@ -2615,81 +2655,118 @@ int btrfs_trim_block_group(struct btrfs_block_group_cache *block_group,
}
entry = tree_search_offset(ctl, start, 0, 1);
- if (!entry)
- entry = tree_search_offset(ctl,
- offset_to_bitmap(ctl, start),
- 1, 1);
-
- if (!entry || entry->offset >= end) {
+ if (!entry) {
spin_unlock(&ctl->tree_lock);
break;
}
- if (entry->bitmap) {
- ret = search_bitmap(ctl, entry, &start, &bytes);
- if (!ret) {
- if (start >= end) {
- spin_unlock(&ctl->tree_lock);
- break;
- }
- bytes = min(bytes, end - start);
- bitmap_clear_bits(ctl, entry, start, bytes);
- if (entry->bytes == 0)
- free_bitmap(ctl, entry);
- } else {
- start = entry->offset + BITS_PER_BITMAP *
- block_group->sectorsize;
+ /* skip bitmaps */
+ while (entry->bitmap) {
+ node = rb_next(&entry->offset_index);
+ if (!node) {
spin_unlock(&ctl->tree_lock);
- ret = 0;
- continue;
+ goto out;
}
- } else {
- start = entry->offset;
- bytes = min(entry->bytes, end - start);
- unlink_free_space(ctl, entry);
- kmem_cache_free(btrfs_free_space_cachep, entry);
+ entry = rb_entry(node, struct btrfs_free_space,
+ offset_index);
+ }
+
+ if (entry->offset >= end) {
+ spin_unlock(&ctl->tree_lock);
+ break;
+ }
+
+ extent_start = entry->offset;
+ extent_bytes = entry->bytes;
+ start = max(start, extent_start);
+ bytes = min(extent_start + extent_bytes, end) - start;
+ if (bytes < minlen) {
+ spin_unlock(&ctl->tree_lock);
+ goto next;
}
+ unlink_free_space(ctl, entry);
+ kmem_cache_free(btrfs_free_space_cachep, entry);
+
spin_unlock(&ctl->tree_lock);
- if (bytes >= minlen) {
- struct btrfs_space_info *space_info;
- int update = 0;
-
- space_info = block_group->space_info;
- spin_lock(&space_info->lock);
- spin_lock(&block_group->lock);
- if (!block_group->ro) {
- block_group->reserved += bytes;
- space_info->bytes_reserved += bytes;
- update = 1;
- }
- spin_unlock(&block_group->lock);
- spin_unlock(&space_info->lock);
-
- ret = btrfs_error_discard_extent(fs_info->extent_root,
- start,
- bytes,
- &actually_trimmed);
-
- btrfs_add_free_space(block_group, start, bytes);
- if (update) {
- spin_lock(&space_info->lock);
- spin_lock(&block_group->lock);
- if (block_group->ro)
- space_info->bytes_readonly += bytes;
- block_group->reserved -= bytes;
- space_info->bytes_reserved -= bytes;
- spin_unlock(&space_info->lock);
- spin_unlock(&block_group->lock);
- }
+ ret = do_trimming(block_group, total_trimmed, start, bytes,
+ extent_start, extent_bytes);
+ if (ret)
+ break;
+next:
+ start += bytes;
- if (ret)
- break;
- *trimmed += actually_trimmed;
+ if (fatal_signal_pending(current)) {
+ ret = -ERESTARTSYS;
+ break;
+ }
+
+ cond_resched();
+ }
+out:
+ return ret;
+}
+
+static int trim_bitmaps(struct btrfs_block_group_cache *block_group,
+ u64 *total_trimmed, u64 start, u64 end, u64 minlen)
+{
+ struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
+ struct btrfs_free_space *entry;
+ int ret = 0;
+ int ret2;
+ u64 bytes;
+ u64 offset = offset_to_bitmap(ctl, start);
+
+ while (offset < end) {
+ bool next_bitmap = false;
+
+ spin_lock(&ctl->tree_lock);
+
+ if (ctl->free_space < minlen) {
+ spin_unlock(&ctl->tree_lock);
+ break;
+ }
+
+ entry = tree_search_offset(ctl, offset, 1, 0);
+ if (!entry) {
+ spin_unlock(&ctl->tree_lock);
+ next_bitmap = true;
+ goto next;
+ }
+
+ bytes = minlen;
+ ret2 = search_bitmap(ctl, entry, &start, &bytes);
+ if (ret2 || start >= end) {
+ spin_unlock(&ctl->tree_lock);
+ next_bitmap = true;
+ goto next;
+ }
+
+ bytes = min(bytes, end - start);
+ if (bytes < minlen) {
+ spin_unlock(&ctl->tree_lock);
+ goto next;
+ }
+
+ bitmap_clear_bits(ctl, entry, start, bytes);
+ if (entry->bytes == 0)
+ free_bitmap(ctl, entry);
+
+ spin_unlock(&ctl->tree_lock);
+
+ ret = do_trimming(block_group, total_trimmed, start, bytes,
+ start, bytes);
+ if (ret)
+ break;
+next:
+ if (next_bitmap) {
+ offset += BITS_PER_BITMAP * ctl->unit;
+ } else {
+ start += bytes;
+ if (start >= offset + BITS_PER_BITMAP * ctl->unit)
+ offset += BITS_PER_BITMAP * ctl->unit;
}
- start += bytes;
- bytes = 0;
if (fatal_signal_pending(current)) {
ret = -ERESTARTSYS;
@@ -2702,6 +2779,22 @@ int btrfs_trim_block_group(struct btrfs_block_group_cache *block_group,
return ret;
}
+int btrfs_trim_block_group(struct btrfs_block_group_cache *block_group,
+ u64 *trimmed, u64 start, u64 end, u64 minlen)
+{
+ int ret;
+
+ *trimmed = 0;
+
+ ret = trim_no_bitmap(block_group, trimmed, start, end, minlen);
+ if (ret)
+ return ret;
+
+ ret = trim_bitmaps(block_group, trimmed, start, end, minlen);
+
+ return ret;
+}
+
/*
* Find the left-most item in the cache tree, and then return the
* smallest inode number in the item.
--
cgit